This research was supported financially by the National Basic Research Program of China (2013CB834502), the National Natural Science Foundation of China (21074066, 51222303), the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (21121004), Tsinghua University Initiative Scientific Research Program (2012Z02131), and an NSFC-DFG joint grant (TRR 61). We acknowledge Prof. Xi Zhang (Tsinghua University) for his stimulating suggestions and discussions, and Prof. Zhibo Li (Institute of Chemistry, Chinese Academy of Sciences) for cryo-TEM measurements.

Keywords:

drug delivery;

γ radiation;

peptide amphiphiles;

responsive gels;

selenium-containing polymers

An overwhelming response: The exposure of a supramolecular hydrogel based on a diselenide-containing polymer and a peptide amphiphile containing a drug moiety to γ radiation led to a gel–sol transition owing to the oxidative cleavage of diselenide bonds in the polymer main chain (see picture). The hydrogel can also act as a UV-mediated drug self-delivery system and suggests a new avenue for combined radio- and chemotherapy.